It has been common practice in the past to pre-assemble elevator cars in the factory, then dismantle the completed cars and re-assemble them in situ. This necessarily involves much double handling and lost time, particularly with separately wired-in units such as the control panel, the indicator lamp assembly and the various proximity switches and controls, all of which have been located at different positions around the car.
Similarly, the corresponding fixed sensors and switches have been mounted in different positions around the elevator shaft and require individual positioning and assembly on site.
The structural components of the car have also been designed so they can be specially assembled to meet particular requirements for door, wall, window or specialized accessory positioning. These may be specified in many different front and back or left and right hand configurations.